From patchwork Mon Dec 28 12:51:16 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg KH X-Patchwork-Id: 352676 Delivered-To: patch@linaro.org Received: by 2002:a02:85a7:0:0:0:0:0 with SMTP id d36csp9796412jai; Mon, 28 Dec 2020 06:41:31 -0800 (PST) X-Google-Smtp-Source: ABdhPJwHEFGSqO+cq2q3t1I9yPxkPqQ5XUdarvI6kJUXwbTzbo5MV5UmDK8N7/KIHAO4LQujc3lc X-Received: by 2002:a17:906:705:: with SMTP id y5mr40485485ejb.428.1609166491627; Mon, 28 Dec 2020 06:41:31 -0800 (PST) ARC-Seal: i=1; a=rsa-sha256; t=1609166491; cv=none; d=google.com; s=arc-20160816; b=XOAXUl8VdAhpSFPqIEtNZfe1dvv7+btzIJYG7v4FF/xeSMZl4wxaX4YzPRkpEkJyVF BJDt0Oz2oM30IrItPrB0NaklUhipo+5YKnYYQgpBcHe07LD2mjGru3D+1JKfnJFiZqAa 5tdo5gx2tZPfW8YnuYR+NQKwu6RYLHlLmeaGd+MVw5xEv4KEv7Xt4uqLwhyXB+H5DXip idVZ9ofyDanOVQuOvbwOf93Z1QTXE4Ic2ULiXa2Gdjv6pONXpQCGC9xXPu0Yt1Ka1fjZ UP6FBbazSHYRZIYJs629iTgKPvB5TOYf7liW+nwucm2GV7UFZ9otT2Ob52YKexwl5DHl 8mRA== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=list-id:precedence:content-transfer-encoding:mime-version :user-agent:references:in-reply-to:message-id:date:subject:cc:to :from:dkim-signature; bh=xhBt+jew5rZ7N62dAcsfgIdbv1v2uIrIgqG49TCiiDE=; b=ri5ukbg0h1UcOmxEHXoBBPRnCd7ANxE+NlrGOYklpInnAUOebZu81i2YGxOItCuHGA qaUcqgKfI3KNwmdjxFgt44auLYmylGB9eWxaCOOjgzwB275C3gnyNpgHsJXH8h+JKS2+ TFPvanHeM/UOVRZTD+VII4XLQQUHS6Xg4ZJ5oPdpJncxoJuRSvOrWN5h9wgUHYh2NKxr YPbUXrRzfr3zkwOjs/4ZA89qGHZkNkIVINxaruGhl+/NsMiuuGeobqbHq3UtWT58Tw/r iqRlRX4ej5FtXUTua9t2LCCAY02CV43PdlT5kAUJYbvyfZ4hex2H+KZE9S9KGo10B8jy ywog== ARC-Authentication-Results: i=1; mx.google.com; dkim=pass header.i=@linuxfoundation.org header.s=korg header.b=yBP92gOI; spf=pass (google.com: domain of stable-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) smtp.mailfrom=stable-owner@vger.kernel.org; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=linuxfoundation.org Return-Path: Received: from vger.kernel.org (vger.kernel.org. [23.128.96.18]) by mx.google.com with ESMTP id os24si19005124ejb.680.2020.12.28.06.41.31; Mon, 28 Dec 2020 06:41:31 -0800 (PST) Received-SPF: pass (google.com: domain of stable-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18; Authentication-Results: mx.google.com; dkim=pass header.i=@linuxfoundation.org header.s=korg header.b=yBP92gOI; spf=pass (google.com: domain of stable-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) smtp.mailfrom=stable-owner@vger.kernel.org; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=linuxfoundation.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2504827AbgL1Ocw (ORCPT + 14 others); Mon, 28 Dec 2020 09:32:52 -0500 Received: from mail.kernel.org ([198.145.29.99]:40806 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2504825AbgL1Ocv (ORCPT ); Mon, 28 Dec 2020 09:32:51 -0500 Received: by mail.kernel.org (Postfix) with ESMTPSA id 12A682242A; Mon, 28 Dec 2020 14:32:09 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1609165930; bh=Obl9+OB4r785Gas4K/VY2GM9eBdcvFh1TwPDckgHm+w=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=yBP92gOInYiDxXN0P+0pLNQaTBnEsX9+jzdrZ5elcDFPs2PX/pLjBCbmtFytnHUWI 3o+0g2ll2HATa7+IcWSpPmkIzc/3kKV4KHk+IrzRPDPZOxpOS7RGvyuIEsPl7S91na Ws24elJ/KaGHmJAc5teWgsogsKoGkbVfetAtgTMk= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Lars-Peter Clausen , Jonathan Cameron , Alexandru Ardelean , Lorenzo Bianconi , Stable@vger.kernel.org Subject: [PATCH 5.10 678/717] iio:light:st_uvis25: Fix timestamp alignment and prevent data leak. Date: Mon, 28 Dec 2020 13:51:16 +0100 Message-Id: <20201228125053.469965466@linuxfoundation.org> X-Mailer: git-send-email 2.29.2 In-Reply-To: <20201228125020.963311703@linuxfoundation.org> References: <20201228125020.963311703@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Jonathan Cameron commit d837a996f57c29a985177bc03b0e599082047f27 upstream. One of a class of bugs pointed out by Lars in a recent review. iio_push_to_buffers_with_timestamp() assumes the buffer used is aligned to the size of the timestamp (8 bytes). This is not guaranteed in this driver which uses an array of smaller elements on the stack. As Lars also noted this anti pattern can involve a leak of data to userspace and that indeed can happen here. We close both issues by moving to a suitable structure in the iio_priv() This data is allocated with kzalloc() so no data can leak apart from previous readings. A local unsigned int variable is used for the regmap call so it is clear there is no potential issue with writing into the padding of the structure. Fixes: 3025c8688c1e ("iio: light: add support for UVIS25 sensor") Reported-by: Lars-Peter Clausen Signed-off-by: Jonathan Cameron Reviewed-by: Alexandru Ardelean Acked-by: Lorenzo Bianconi Cc: Link: https://lore.kernel.org/r/20200920112742.170751-3-jic23@kernel.org Signed-off-by: Greg Kroah-Hartman --- drivers/iio/light/st_uvis25.h | 5 +++++ drivers/iio/light/st_uvis25_core.c | 8 +++++--- 2 files changed, 10 insertions(+), 3 deletions(-) --- a/drivers/iio/light/st_uvis25.h +++ b/drivers/iio/light/st_uvis25.h @@ -27,6 +27,11 @@ struct st_uvis25_hw { struct iio_trigger *trig; bool enabled; int irq; + /* Ensure timestamp is naturally aligned */ + struct { + u8 chan; + s64 ts __aligned(8); + } scan; }; extern const struct dev_pm_ops st_uvis25_pm_ops; --- a/drivers/iio/light/st_uvis25_core.c +++ b/drivers/iio/light/st_uvis25_core.c @@ -232,17 +232,19 @@ static const struct iio_buffer_setup_ops static irqreturn_t st_uvis25_buffer_handler_thread(int irq, void *p) { - u8 buffer[ALIGN(sizeof(u8), sizeof(s64)) + sizeof(s64)]; struct iio_poll_func *pf = p; struct iio_dev *iio_dev = pf->indio_dev; struct st_uvis25_hw *hw = iio_priv(iio_dev); + unsigned int val; int err; - err = regmap_read(hw->regmap, ST_UVIS25_REG_OUT_ADDR, (int *)buffer); + err = regmap_read(hw->regmap, ST_UVIS25_REG_OUT_ADDR, &val); if (err < 0) goto out; - iio_push_to_buffers_with_timestamp(iio_dev, buffer, + hw->scan.chan = val; + + iio_push_to_buffers_with_timestamp(iio_dev, &hw->scan, iio_get_time_ns(iio_dev)); out: